It’s time to boldly go back to the past.

Publisher Perfect World revealed Agents of Yesterday today, the third expansion for Star Trek: Online. It allows players to create a captain and command a ship in the same timeline as the original Star Trek series (you know, the one with Spock and Kirk from the ’60s). It launches this summer for PC. Star Trek Online originally came out back in 2010. New content, especially expansions, can bring new and old players back to the free-to-play online game.

“Star Trek Online has been able to explore other eras in the franchise from Star Trek: Enterprise to Star Trek: Voyager, while continuing to add to the core Star Trek narrative,” said Steve Ricossa, executive producer of Star Trek Online, in a press release sent to GamesBeat. “The 50th Anniversary of Star Trek presents a unique opportunity and challenge for our team, to faithfully venture back in time to one of the most iconic science-fiction settings and eras in television history. Combining Star Trek: The Original Series with Star Trek Online allows us to take players on some new and unique adventures in a time period that is beloved by fans.”

The expansion features Walter Koenig, the actor who portrayed Chekov in the original show, returning to reprise the role. Chris Doohan, the son of James Doohan, plays Scotty. You can watch the announcement trailer for Agents of Yesterday below.